Patent GB-695559-A (GB)
Title: Improvements in the manufacture and treatment of textile yarns and filaments
Inventor: HAWTIN SELWYN GEORGE
IPC: D01D5/06
Filed: 1950-03-28
Abstract: A group of artificial filaments is passed upwardly through a liquid with the filaments travelling in separate nearly parallel paths and coming together to form a yarn at a point which is above the surface of the liquid when the yarn is free from twist but which is lowered to a position nearer to the surface of the liquid, or even below that surface, by passing the yarn over a pulley situated above the surface of the liquid and fixed skew with respect to the natural plane of the yarn so as to cause the <PICT:0695559/IV (a)/1> yarn when it reaches the pulley to make contact with one side of the groove, and at a later stage in its passage over the pulley to make contact with the bottom of the groove.  A false twist is thus imparted to the yarn. The lowering of the point at which the filaments come together to form a yarn has the effect of reducing or eliminating the column of liquid which is drawn up by the filaments from the surface of the main body of liquid through which they pass.  The process is applicable to the production of artificial filaments by an upward wet-spinning operation, e.g. to the production of filaments from acetone solutions of cellulose acetate by extrusion into an aqueous solution of acetone or diethylene glycol diacetate.  It is applicable to the wet-spinning of solutions of polyvinyl compounds.  The coagulating medium may flow in the same direction as the filaments or in a counter- or cross-current.  The process is also applicable to the treatment of filaments with dyeing or other liquids.  As shown, filaments issue from nozzle 7 into extrusion chamber 1 and setting chamber 2 through which flows an upward current of coagulating liquid. Perforated plate 8 reduces turbulence of liquid around the nozzle 7.  The filaments converge to form a yarn 17 which passes over freely-mounted pulleys 3, 4, and godet 5 to a winding device. Pulley 3 is mounted in fork 12 which is attached to rod 13.  This rod may be rotated in block 14 so as to set the pulley 3 askew with respect to the plane of travel of the yarn, which first makes contact with one side of the groove of the pulley and at a later stage in its passage over the pulley makes contact with the bottom of the groove.  The groove of the pulley is preferably of V-section and has its greatest width not more than 3 times its depth.  If desired the pulley 3 may be positively driven.ALSO:Apparatus for the treatment of textile filaments with liquids comprises a container for a liquid, means for passing a number of filaments upwardly through the liquid in separate nearly parallel paths and for bringing them together <PICT:0695559/IV (c)/1> to form a yarn, and a grooved pulley situated above the surface of the liquid and adapted to make contact with the yarn in advance of any other structure with which the yarn comes into contact, the pulley being so mounted that it is or can be fixed in a position skew with respect to the natural plane of the yarn so as to cause the yarn when it reaches the pulley to make contact with one side of the groove, and at a later stage in its passage over the pulley to make contact with the bottom of the groove.  A false-twist is thus imparted to the yarn and the point at which the filaments come together to form the yarn is lowered to a position nearer to the surface of the liquid or even below the surface.  The column of liquid which tends to be drawn up above the surface of the main body of treating liquid by the group of filaments is thereby reduced or eliminated.  The apparatus may be used for the treatment of filaments with softening, sizing, or dyeing liquids, or liquids for shrinking or imparting anti-static properties.  As shown, filaments pass upwardly through chamber 2 where they are treated with a liquid which flows in the same direction.  The filaments converge to form a yarn 17 which passes over freely-mounted pulleys 3, 4, and godet 5 to a winding device. Pulley 3 is mounted in a fork 12 which is attached to rod 13. This rod may be rotated in block 14 to set the pulley 3 askew with respect to the plane of travel of the yarn.  The groove of the pulley is preferably of V-section and has its greatest width not more than 3 times its depth.  If desired the pulley may be positively driven.